A large integrated packet processing device such as a network flow processor integrated circuit may include multiple smaller specialized processors, where each such smaller processor is specially adapted and designed and/or specially programmed to do a particular type of packet processing. The large integrated device may receive packets on several different input ports, and may do initial processing on those packets in different initial processing circuits located in different places on the integrated circuit. For further processing, each packet then passes from one of the initial processing circuits to an appropriate one or more of the specialized processors. After processing by a specialized processor, a packet is forwarded to one of a plurality of output processing circuits, that in turn causes the packet to be output from the integrated circuit. If a packet received on a first input port and a first associated initial processing circuit is of a particular type, then it may be forwarded to one particular specially adapted processor. If another packet of a different type is received onto the same first input port, then that packet may be forwarded to another of the specialized processors. Similarly, a packet received on a second input port and a second associated initial processing circuit may be of the type that is to be further processed by same first specially adapted processor. In this way, some of the packets received on several different input ports and initial processing circuits may all be forwarded to the same one specialized processor. These packets may, for example, be written into different queues in a holding memory, or may be received by different ports of a multi-ported holding memory, or may be pushed into cooperating FIFO holding memories, or may be loaded into assigned buffers in a holding memory. Once a packet is in the holding memory, the specialized processor accesses the packet and performs the necessary further processing. The specialized processor is somehow made aware of the presence of the packet in the holding memory, or is otherwise provided with the packet. Throughput can be increased in a variety of ways, including by providing multiple specialized processors that perform the same specialized task. After being processed by a specialized processor, the packet is forwarded to an appropriate one of the output processing circuits, and is then output from the integrated circuit.